最基础的高斯消元(浮点数)版，可以用来测试模板
这个模板直接从大白书上敲下来的，感觉还行
讲解一下这个模板的用法
构造的是A*r=b
行列的下标都是从0开始
A[i][j]是增广矩阵的第i行的第j列
b存放在对应的A[i][n]里面
调用函数后，A[i][n]里面存放的就是对应的r矩阵了
#include<cstdio>
#include<map>
#include<set>
#include<cmath>
#include<cstring>
#include<queue>
#include<stack>
#include<cctype>
#include<vector>
#include<functional>
#include<algorithm>using namespace std;
typedef long long LL;
typedef pair<int, int> PII;const int MX = 100 + 5;
const int INF = 0x3f3f3f3f;
typedef double Matrix[MX][MX];Matrix A, S;void gauss(Matrix A, int n) {int i, j, k, r;for(i = 0; i < n; i++) {r = i;for(int j = i + 1; j < n; j++) {if(fabs(A[j][i]) > fabs(A[r][i])) r = j;}if(r != i) for(j = 0; j <= n; j++) swap(A[r][j], A[i][j]);for(k = i + 1; k < n; k++) {double f = A[k][i] / A[i][i];for(j = i; j <= n; j++) A[k][j] -= f * A[i][j];}}for(i = n - 1; i >= 0; i--) {for(j = i + 1; j < n; j++) {A[i][n] -= A[j][n] * A[i][j];}A[i][n] /= A[i][i];}
}int main() {//freopen("input.txt", "r", stdin);int m, n, d, first = true;while(~scanf("%d%d%d", &n, &m, &d), m) {memset(A, 0, sizeof(A));for(int i = 0; i < m; i++) {for(int j = 0; j < n; j++) {scanf("%lf", &S[i][j]);}}for(int i = 0; i < m; i++) {for(int j = 0; j < n; j++) {int cnt = 0, nx, ny;for(int dx = -d; dx <= d; dx++) {nx = dx + i;if(nx < 0 || nx >= m) continue;int p = d - abs(dx);for(int dy = -p; dy <= p; dy++) {ny = dy + j;if(ny < 0 || ny >= n) continue;cnt++;A[i * n + j][nx * n + ny] = 1;}}A[i * n + j][m * n] = cnt * S[i][j];}}gauss(A, m * n);if(first) first = false;else printf("\n");for(int i = 0; i < m; i++) {for(int j = 0; j < n; j++) {printf("%8.2lf", A[i * n + j][m * n]);}printf("\n");}}return 0;
}